By using the new isothermal plateau fission-track method of dating tephra layers developed by Westgate, by applying a proven detailed method for characterizing (fingerprinting) individual tephra layers, and by outlining the paleomagnetostratigraphy of the loess, it is planned to develop a reliable and detailed chronostratigraphic framework for the 3 million year loess sequence with the abundant tephra beds, and plant and animal remains near Fairbanks, Alaska. The long-studied loess exposures will now be able to be tied together to create a veritable "Rosetta Stone", permitting the dating of detailed geologic, biologic, and climatic records of environmental change in interior Alaska for late Cenozoic time. This record then can be widely correlated from the Yukon to eastern Siberia. The State of Alaska has created a Loess Study Preserve at Gold Hill near Fairbanks where the loess record extends back 3 million years, perhaps the oldest in the world. Of the three detailed investigation trenches dug at this site, only one is completely studied; paleomagnetic dating is required on the other two. Also, only two of the many tephra have been dated here. Continued detailed sedimentologic, tephrochronologic, and paleomagnetostratigraphic work at this and other exposures near Fairbanks will strengthen the preliminary chronostratigraphic framework outlining the long, cold time periods of loess deposition in tundra environments interspersed with forest environments of interglacial times.
